In order to test whether the vaccination protects the horses from developing insect bite hypersensitivity a challenge experiment has to be performed where the vaccine is tested under real conditions.
Twenty-seven horses have been vaccinated at Keldur intralymphatic three times with 4 week interval with nine purified allergens in Alum/MPL. The horses were transported to Switzerland 16th of March 2020. They will be kept in Culicoides areas and be naturally exposed to the midges for 3 summers. No protection is allowed. The horses will be monitored, blood samples taken on a regular basis and clinical examination performed to look for evidence of IBH supervised by Dr Eliane Marti Vetsuisse Faculty, University of Bern. For more information see Horses of Iceland.
Unvaccinated control horses were not exported at the same time as it has be shown that at least 50% of horses exported from Iceland to Culicoides infested areas and not protected develop IBH (Björnsdóttir et al., 2006; Torsteinsdottir et al., 2018).
Picture: Gunnar Freyr Gunnarsson